:root{--color-background:#fff;--color-surface:#f6f6f6;--color-text:#171717;--color-text-muted:#666;--color-border:#ddd;--color-accent:#202020;--font-sans:Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;--font-mono:"SFMono-Regular", Consolas, "Liberation Mono", monospace;--space-1:.25rem;--space-2:.5rem;--space-3:.75rem;--space-4:1rem;--space-6:1.5rem;--space-8:2rem;--space-12:3rem;--space-16:4rem;--radius-sm:.375rem;--radius-md:.75rem;--content-width:72rem;--transition-fast:.16s ease}@media (prefers-reduced-motion:reduce){:root{--transition-fast:0s}}*,:before,:after{box-sizing:border-box}html{font-family:var(--font-sans);color:var(--color-text);background:var(--color-background);text-rendering:optimizelegibility;line-height:1.5}body{min-width:20rem;margin:0}img,svg,video{max-width:100%;display:block}button,input,textarea,select{font:inherit}a{color:inherit}:focus-visible{outline-offset:3px;outline:2px solid}:root{color-scheme:dark;--flap-ink:#eaf3ff;--flap-soft:#a1abc9;--flap-teal:#82f4e2;--flap-purple:#a89bff;--flap-deep:#080e21}*{box-sizing:border-box}body{background:var(--flap-deep);min-width:320px;color:var(--flap-ink);margin:0;font-family:Inter,ui-sans-serif,system-ui,-apple-system,Segoe UI,sans-serif}button{font:inherit;cursor:pointer}button:focus-visible,canvas:focus-visible{outline:3px solid var(--flap-teal);outline-offset:4px}.flap-page{background:radial-gradient(at 77% 26%,#232552 0%,#0000 42%),radial-gradient(at 17% 95%,#132e40 0%,#0000 39%),#080e21;min-height:100svh;position:relative;overflow:hidden}.flap-page:before{pointer-events:none;content:"";opacity:.23;background-image:linear-gradient(#50618b 1px,#0000 1px),linear-gradient(90deg,#50618b 1px,#0000 1px);background-size:72px 72px;position:absolute;inset:0;mask-image:linear-gradient(#0000,#000 20%,#0000 86%)}.site-header{z-index:1;border-bottom:1px solid #ffffff13;justify-content:space-between;align-items:center;max-width:1280px;margin:auto;padding:29px clamp(20px,4.7vw,62px);display:flex;position:relative}.brand{color:#f4f8ff;letter-spacing:.24em;align-items:center;gap:12px;font-size:17px;font-weight:800;display:flex}.brand-mark{width:35px;height:35px;color:var(--flap-teal);letter-spacing:-.1em;background:#83fce612;border:1px solid #8cf8ee75;border-radius:11px;place-items:center;padding-right:3px;font-size:18px;font-weight:900;display:inline-grid;box-shadow:0 0 23px #78ffeb18}.header-note{color:#a0adca;letter-spacing:.22em;font-size:11px;font-weight:700}.main-area{z-index:1;grid-template-columns:minmax(0,1fr) minmax(340px,490px);align-items:center;gap:clamp(36px,6vw,85px);max-width:1280px;margin:auto;padding:40px clamp(20px,4.7vw,62px) 55px;display:grid;position:relative}.intro{padding-bottom:30px}.eyebrow{color:var(--flap-teal);letter-spacing:.24em;align-items:center;gap:10px;margin:0 0 22px;font-size:11px;font-weight:800;display:inline-flex}.eyebrow:before{content:"";background:var(--flap-teal);width:22px;height:2px;display:block}.intro h1{color:#f8fbff;letter-spacing:-.065em;margin:0;font-size:clamp(55px,7vw,104px);font-weight:900;line-height:.98}.intro h1 span{background:linear-gradient(100deg,#7beedc 0%,#86cbf9 48%,#b39afd 86%);color:#0000;-webkit-background-clip:text;background-clip:text;display:block}.intro-copy{color:#b7c1d8;max-width:440px;margin:28px 0 30px;font-size:16px;line-height:1.7}.intro-actions{flex-wrap:wrap;gap:11px;display:flex}.primary-button,.secondary-button{border:1px solid #0000;border-radius:12px;padding:15px 21px;font-size:13px;font-weight:800}.primary-button{color:#08212b;background:linear-gradient(95deg,#83f9dc,#a0e8ff);box-shadow:0 8px 36px #70fbda21}.primary-button:hover{filter:brightness(1.06)}.secondary-button{color:#edf4ff;background:#ffffff0b;border-color:#ffffff24}.secondary-button:hover:not(:disabled){background:#ffffff1d}.secondary-button:disabled{cursor:not-allowed;color:#747e9b}.how-to{border-top:1px solid #ffffff21;margin-top:36px;padding-top:25px}.how-title{color:#c6d0e7;letter-spacing:.2em;margin:0 0 17px;font-size:11px;font-weight:900}.how-line{color:#aab5d2;flex-wrap:wrap;align-items:center;gap:12px;font-size:13px;line-height:1.5;display:flex}.key{color:#ddfcf8;text-align:center;background:#ffffff0b;border:1px solid #ffffff30;border-radius:7px;min-width:47px;padding:6px 10px;font-size:11px;font-weight:800;display:inline-block}.metrics{flex-wrap:wrap;gap:26px;margin-top:30px;display:flex}.metric{flex-direction:column;gap:5px;display:flex}.metric-label{color:#a3aac4;letter-spacing:.15em;font-size:10px;font-weight:800}.metric-value{color:#f4fbff;font-variant-numeric:tabular-nums;font-size:31px;font-weight:900;line-height:1}.metric-value.is-best{color:#8bf8e0}.board-column{justify-self:center;width:min(100%,485px)}.board-header{justify-content:space-between;align-items:center;padding:0 3px 12px;display:flex}.board-title{color:#d9e6fa;letter-spacing:.16em;font-size:11px;font-weight:800}.sound-button{color:#b7c4e2;background:0 0;border:1px solid #ffffff2b;border-radius:8px;padding:8px 11px;font-size:11px;font-weight:700}.sound-button:hover{background:#ffffff13}.game-shell{background:linear-gradient(145deg,#718aff45,#85ffdd38 48%,#5f678c39);border:1px solid #b6cbff3a;border-radius:27px;width:100%;padding:11px;box-shadow:0 18px 85px #0007,0 0 70px #6c76ff18}.game-screen{aspect-ratio:420/680;background:#17264a;border-radius:17px;position:relative;overflow:hidden}#flap-canvas{touch-action:manipulation;user-select:none;width:100%;height:100%;display:block}.game-hud{z-index:1;pointer-events:none;justify-content:space-between;align-items:center;display:flex;position:absolute;top:20px;left:19px;right:19px}.game-hud-label{letter-spacing:.16em;color:#defffe;text-shadow:0 1px 10px #000;font-size:10px;font-weight:900}.game-hud-dot{background:#95ffdd;border-radius:100px;width:7px;height:7px;box-shadow:0 0 10px #95ffdd}.game-overlay{z-index:2;text-align:center;background:linear-gradient(#08152b6a,#071024ba);align-content:center;justify-items:center;padding:30px;transition:opacity .15s;display:grid;position:absolute;inset:0}.game-overlay.is-hidden{opacity:0;pointer-events:none}.overlay-symbol{color:#a6fff1;background:#7efbe323;border:1px solid #b4fff77b;border-radius:23px;place-items:center;width:78px;height:78px;margin-bottom:17px;font-size:43px;font-weight:900;display:grid;transform:rotate(-10deg);box-shadow:inset 0 0 34px #80fff125,0 0 40px #80fff11d}.overlay-eyebrow{color:#8cf8e0;letter-spacing:.22em;font-size:11px;font-weight:900}.overlay-title{letter-spacing:-.045em;color:#fff;margin:12px 0 9px;font-size:clamp(29px,4vw,39px);font-weight:900;line-height:1.1}.overlay-description{color:#d3ddec;max-width:275px;margin:0 0 22px;font-size:14px;line-height:1.5}.overlay-button{color:#0b2933;background:#84f4df;border:none;border-radius:11px;padding:13px 21px;font-weight:900}.overlay-button:hover{background:#b1ffee}.board-footer{color:#8e9cba;justify-content:space-between;gap:15px;padding:13px 3px 0;font-size:11px;display:flex}.footer{color:#8692b0;letter-spacing:.07em;border-top:1px solid #ffffff13;max-width:1280px;margin:0 auto;padding:14px clamp(20px,4.7vw,62px) 24px;font-size:11px}.sr-only{clip:rect(0, 0, 0, 0);white-space:nowrap;border:0;width:1px;height:1px;margin:-1px;padding:0;position:absolute;overflow:hidden}@media (width<=870px){.main-area{grid-template-columns:1fr;gap:33px;padding-top:44px}.intro{padding-bottom:0}.intro h1{font-size:clamp(58px,12vw,100px)}.intro-copy{margin-top:20px}.how-to{margin-top:25px}.board-column{max-width:500px}}@media (width<=510px){.site-header{padding:18px 20px}.brand{letter-spacing:.15em;font-size:13px}.header-note{letter-spacing:.06em;font-size:9px}.main-area{padding:35px 14px}.intro{padding:0 6px}.intro h1{font-size:clamp(55px,16vw,79px)}.intro-copy{font-size:14px;line-height:1.55}.how-line{gap:7px}.metrics{gap:35px}.board-column{width:100%}.game-shell{border-radius:21px;padding:7px}.game-screen{border-radius:15px}.board-header,.board-footer{padding-left:5px;padding-right:5px}.footer{padding:18px 20px 24px}}@media (prefers-reduced-motion:reduce){.game-overlay{transition:none}}